Fixing Shower Tray to Floorboards

Discussion in 'Plumbers' Talk' started by closetothebrink, Aug 30, 2005.

  1. closetothebrink

    closetothebrink New Member

    I'm fitting a 900x900 stone resin shower tray in an upstairs bathroom with conventional T&G floorboards. I'm fitting the tray at floor level with the waste going under the boards.

    The fitting instructions aren't clear, but say to remove "suspended" flooring & replace with 18mm marine ply, before bedding the tray on sand & cement. Is it really necessary to pull up the T&G boards and replace with ply, or can the tray be bedded directly onto the T&G boards?

    The instructions also refer to a "tiling upstand". What's that? I was planning to tile down to the tray & finish with silicon where the tiles meet the tray.

    Many thanks in advance for any advice.
  2. handyman.

    handyman. New Member

    dont get why you would need to replace good solid floorboards (if they are) with ply. Also marine ply is an odd choice........its not a boat.(ie no salt)
  3. always_learning

    always_learning New Member

    I don't think it is necessary to pull up the existing flooring, as long as it is solid, and fairly level....?
    Marine ply isn't necessary, WBP wil do OK, the manufacturers are woried about water ingress, ie no chipboard!, as it can expand and go 'fluffy'... and the tray being supported properly.

    The upstand is the vertical 'lip' at the edge of the tray, if there is one? You tile down, inside this, to the 'horizontal' part of the tray, to prevent water getting underneath/behind your tiles.
    I have had success with self levelling compound on a variety of flooring, as long as the tray is well supported it can't crack under load, or go anywhere... :)
  4. jakeofalltrades

    jakeofalltrades New Member

    Last year I did the same.
    I laid the shower tray on a mix of 3 to 1 and put SBR additive in the mix.
  5. Leave the Boards and fit 18mm WBP on it, just make sure you get a long tail waste that goes through the whole lot.

    I use rapidset flexible tile adhesives to bed the trays, means I haven't got to wait 24hrs to do anymore work around them, and it's far stronger that a bed of sand/cement. Although the sand/cement is fine if time isn't an issue.
  6. handyman.

    handyman. New Member

    mudster, is there anything you dont use rapidset flex for?? ;)
  7. closetothebrink

    closetothebrink New Member

    Thanks for the advice guys. Re mudster's suggestion - I thought of putting the 18mm ply on top of the boards, but as the boards are in good nick I'm planning to tile directly onto the boards using Topps wood-fix tile adhesive, so this would leave the ply standing proud of the tiles. So is my best option to bed the tray directly to the boards?
  8. bathstyle

    bathstyle Active Member

    Sitting the Tray directly onto the floorboard is absolutley fine.

    I'm not a great fan of using sand/cement but that's what the manufacturer recommends so they must know, some manufacturers recommend silicone sealant under the tray but this is only suitable if your floor under the tray is level or thereabouts.

    As for using tile adhesives directly onto the boards, it's not my preferred method, I will only lay onto 12mm ply.

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